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Vulnerabilities

Vulnerability · CVE-2020-0688

Microsoft Exchange Server Validation Key Remote Code Execution Vulnerability

Published Feb 11, 2020 · catalog updated Jun 16, 2026 · Microsoft Exchange Server

Patch now

CVE-2020-0688 is in the CISA known-exploited catalog, due May 3, 2022. Confirm Microsoft Exchange Server against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
Severity
High8.8
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
99.96%
Remediation
Remediation guidance
Affected products
cpe microsoft/exchange server · vendor Microsoft Exchange Server

A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe microsoft/exchange server2010
  • cpe microsoft/exchange server2013
  • cpe microsoft/exchange server2016
  • cpe microsoft/exchange server2019
  • vendor Microsoft Exchange Serverversion unspecified

How to fix CVE-2020-0688

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2020-0688 is in the CISA known-exploited catalog, due May 3, 2022. Confirm Microsoft Exchange Server against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Compare what you have installed with microsoft/exchange server 2010; microsoft/exchange server 2013; microsoft/exchange server 2016; microsoft/exchange server 2019. Apply updates per vendor instructions.

What should an analyst verify?

CWE-287: Improper Authentication. EPSS 99.96%. The CISA KEV listing is the exploitation evidence. A public exploit reference is linked in Sources. That is not the same as confirmed exploitation. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Feb 11, 2020 · Catalog

    Detected

    A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.

  2. Nov 3, 2021 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. May 3, 2022 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Jun 16, 2026 · Catalog

    Updated

    A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.

Sources

  • CISA KEVConfirmed exploitationCVE-2020-0688

    Microsoft Exchange Server Validation Key fails to properly create unique keys at install time, allowing for remote code execution.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2020-0688

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2020-0688

    30-day exploitation probability 100.0%

    first.org
  • Exploit DatabasePublic exploit reference48153

    Public archive entry. The exploit body is not stored here.

    exploit-db.com
  • Exploit DatabasePublic exploit reference48168

    Public archive entry. The exploit body is not stored here.

    exploit-db.com
  • Metasploit ModulesPublic exploit moduleexploit_windows/http/exchange_ecp_viewstate

    Public module reference (excellent). Module source is not copied into this catalog.

    rapid7.com
  • NIST NVDVulnerability recordCVE-2020-0688

    A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.

    nvd.nist.gov
  • Packet Storm SecurityCited referencehttp://packetstormsecurity.com/files/156592/Microsoft-Exchange-2019-15.2.221.12-Remote-Code-Execution.html

    Packet Storm link already published on the finding.

    packetstormsecurity.com
  • Packet Storm SecurityCited referencehttp://packetstormsecurity.com/files/156620/Exchange-Control-Panel-Viewstate-Deserialization.html

    Packet Storm link already published on the finding.

    packetstormsecurity.com
  • VulnCheck KEVConfirmed exploitationCVE-2020-0688

    Microsoft Exchange Server Validation Key fails to properly create unique keys at install time, allowing for remote code execution.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.